MacDonald says there are twice as many fire trucks than ambulances, which means the response time is faster if a fire truck responds. For example: In Brighton/Allston, there is one ambulance and five fire trucks. The city’s fire trucks are staffed with trained firefighters and EMTs with oxygen and defibrillators, MacDonald said.

The truck usually arrives on scene first  within four minutes on average — and is able to stabilize the victim until the ambulance arrives.

Ladder trucks and engines take turns responding to medical calls, MacDonald explained, because the department wants to keep the ladder truck firefighters proficient. If the department only sent out engines, ladder truck operators would not get enough practice responding to medical emergencies.